<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1, user-scalable=no">
    <meta http-equiv="X-UA-Compatible" content="ie=edge,chrome=1">
    <meta name="author" content="杨宁争">
    <title></title>
    <style>
        .main {
            border: 2px solid greenyellow;
            width: 760px;
            height: 314px;
            margin: 100px auto;
        }

        ul {
            margin: 0;
            padding: 0;
            list-style: none;
            text-align: center;
        }

        li {
            width: 130px;
            height: 130px;
            float: left;
            border: 1px solid royalblue;
            ;
            margin: 10px 10px;
            position: relative;
            background-color: orange;
        }

        img {
            width: 130px;
            height: 130px;
            top: 0;
            left: 0;
        }
    </style>
</head>

<body>

    <div class="main">
        <ul>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
        </ul>
        <ul>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
            <li>
                <img src="" alt="">

            </li>
        </ul>
    </div>
</body>

</html>
<script>
    var lis = document.querySelectorAll('li');
    var imgs = document.querySelectorAll('img');
    var imgarr = ["big_1.jpg",
        "big_2.jpg",
        "big_3.jpg",
        "big_4.jpg",
        "big_5.jpg",
        "big_6.jpg",
        "big_7.jpg",
        "big_8.jpg",
        "big_9.jpg",
        "big_10.jpg"
    ];
    for (var i = 0; i < lis.length; i++) {
        lis[i].index = i;
        lis[i].onmouseover = function () {
            imgs[this.index].src = imgarr[this.index];

        }
        lis[i].onmouseout = function () {
            imgs[this.index].src = '';

        }
    }
</script>